In this paper, effects of high temperatures on the
compressive strength of concrete were investigated with the aim to produce a
fire resistant concrete. Thus, the mixture groups were determined by replacing
pumice for ordinary aggregate in the ratios of 25, 50, 75 and 100% in volume.
The temperature values were chosen as 150, 300, 450, 600 and 750°C.
The effects of heating duration over the compressive strength were also
examined, and the different types of concrete mixtures were heated for one
hour, three hours and five hours periods for each temperature values. It was
observed that concrete properties were deteriorated at 150°C and
the specimens began to lose some of their initial strengths at this
temperature. Though a considerable strength lose was not seen between 150-300°C,
all types of concrete mixtures continued to lose their compressive strength
after 300°C.
Every concrete mixture lost a significant part of their initial strength when
the temperature is reached up to 750°C. When the lightweight aggregate ratio is increased for
each temperature value, the loss of compressive strength of the concrete
compared to the initial strength was decreased. It was found that the heating
duration does not affect the strength loss significantly but a high temperature
is a more significant parameter on the strength loss.